1. Field of the Invention
The present invention relates to an alarm generation method and apparatus, and in particular, it relates to an alarm generation method and apparatus for generating an alarm to a driver of a vehicle.
2. Description of the Related Art
With a known technology (see Japanese Unexamined Patent Application Publication 11-232411), a searching radio wave is continuously emitted from on-vehicle equipment to a mobile device carried by a pedestrian or a cyclist. Upon receipt of the radio wave, the mobile device carried by the pedestrian or the cyclist increases its output power. Thus, a receiving device included in the on-vehicle equipment searches for the output power and detects the pedestrian or the cyclist. With this technology, a driver is accurately informed of the approach of a passerby on a poorly visible street or at a pedestrian-crossing and is assisted in performing safe driving.
Unfortunately, the foregoing known technology has a problem, for example, that the on-vehicle equipment must continuously emit a searching radio wave to the mobile device carried by the pedestrian or the cyclist, resulting in a needless consumption of electric energy and also, an adverse effect on other electronic devices due to emission of an unnecessary radio wave.
Also, while placing importance on detecting a pedestrian, a bicycle, or the like as accurately as possible, the known technology is incapable of sensing a dangerous situation in which the pedestrian or the bicycle moves out into the roadway in order to avoid an obstacle on a sidewalk and informing a driver of the situation. In other words, when a utility pole or the like is installed on a narrow sidewalk, two or more pedestrians have difficulty in proceeding along the narrow sidewalk side by side, thereby causing the pedestrian or the bicycle to likely move out into the roadway. Hitherto, such a situation could not be sensed so as to notify a driver to pay attention to it.